1. Field of Invention
This invention relates in general to offshore drilling and production equipment and in particular to a subsea tree assembly with a configurable master valve block.
2. Description of Related Art
Subsea wellhead assemblies are typically used in the production of hydrocarbons extracted from subterranean formations below the seafloor. Subsea wellhead assemblies generally comprise a wellhead housing disposed at a wellbore opening, where the wellbore extends through one or more hydrocarbon producing formations. Casing and tubing hangers are landed within the housing for supporting casing and production tubing inserted into the wellbore. The hangers can have dual bore or mono bore configurations. The casing lines the wellbore, thereby isolating the wellbore from the surrounding formation. Tubing typically lies concentric within the casing and provides a conduit for producing the hydrocarbons entrained within the formation. Wellhead assemblies also typically include subsea trees, also known as Christmas trees, connected to the upper end of the wellhead housing. The subsea trees control and distribute the fluids produced from the wellbore.
Subsea trees are installed on the wellhead housing, tubing head, or tubing hanger spool. The subsea tree includes a valve block that contains flow lines, valves, and actuators for controlling the flow of fluid into and out of the wellhead assembly, such as controlling and distributing the fluids produced from the wellbore. Valve blocks can have a variety of configurations and are sometimes customized, designed, and fabricated as one-off or limited production equipment.